What to do if a shirt is too low?

I have 2 really cute shirts but they're kind of low. If I pull them up, they look fine but when I bend over, you can see everything because it's pretty loose. It's polyester so it won't shrink :l I can't go to a tailor and I really don't like the way a cami looks under it. Is there anything else I can do? Do you think I could just wear it as is if I keep it pulled up?